Fuel injection apparatus



May 6, 1952 T. s. CHMURA ETAL 2,595,539

FUEL INJECTION APPARATUS Filed Nov. 12, 1948 1 1' INVENTORS.

THEODORE s. CHMU'IZA OEGE. B wooD,Jr2.

/ A TTOP/VL'X Patented May 6, 1952 FUEL INJECTION APPARATUS Theodore S. Qhmura,

Wood, in,

Mass.,

Ghicopee, and George B.

Springfield, Mass assignors to American Bosch Corporation,

Springfield,

a corporation of New York 1 Application November 12, 1948, Serial No. 59,504

4 Claims. 1

This invention relates to fuel injection apparatus and relates particularly to a new and improved form of fuel injection nozzle;

An object of the invention is to provide a new and improved fuel injection nozzle which is relatively simple and economical in construction yet eflicient in operation.

Another object of the invention is to provide a new and improved fuel injection nozzle having a self-seating or centering valve.

Another object of the invention is to provide a new and improved fuel injection nozzle wherein the alignment between the bore for the valve stem and the seat for the valve tip need not be in perfect alignment to prevent leakage because of the self-aligning or seating construction of the valve tip.

Another object of the invention is to provide a fuel injection nozzle of the type set forth wherein the extreme accuracy required for obtaining seat concentricity with the valve bore is eliminated.

Another object of the invention is to provide a fuel injection nozzle of the type set forth wherein the valve tip may be interchanged without need for changing of the valve body.

Other objects and advantages of the invention will be apparent from the following description taken in connection with the accompanying drawings and it will be understood that changes may be made in the details of construction and arrangement of parts, as the preferred forms have been given by way of illustration only.

Referring to the drawings:

Fig. 1 is an exploded sectional view of one form of nozzle embodying the invention;

Fig. 2 is a sectional view of a nozzle generally similar to that shown in Fig. l but with a slightly different nozzle tip; and

Fig. 3 is a sectional view of a modified form of nozzle embodying the invention.

Referring to the drawings wherein similar reference characters designate corresponding parts throughout the several views, there is shown in Fig. 1 a multiple hole type nozzle embodying the invention and which consists of the nozzle body I having the central bore 2 and the supply duct 3 adapted to supply fuel to the sump t in the nozzle tip which has a, plurality of openings 5 through which fuel is adapted to be supplied to the combustion chamber.

The valve actuating member or piston G is adapted to be positioned within the bore 2 as shown in Fig. 2. This member 6 has the leak-off groove 1 and the leak-off duct 8 for the purpose hereinafter described.

The nozzle embodying the invention comprises 2 a separate self-centering valve tip 9 having the seat It adapted to seat on the seat I I of the nozzle 1 to control the flow of fuel through the nozzle.

The coupling I2 is provided for securing the nozzle on the nozzle holder as hereinafter described.

In the form of the invention shown in Fig. 2, the nozzle comprises a tubular support l3 in which is positioned the nozzle body M over the seat member I 5 which is adapted to be supported by the flange 16 on the body l3 and having the single central opening I! for the discharge of fuel into the combustion chamber.

In this form of the invention the tubular support [3 is provided with the threaded extension 18 for securing the nozzle to the nozzle holder as hereinafter described.

In this form of the invention the bore 2 is provided in the nozzle body l4 and adapted to receive the valve actuating member Bas previously described in connection with the form of the invention shown in Fig. 1 and the member [5 is provided with the seat l9 adapted to be engaged by the seat Ill on the valve tip 9 to control the flow of fuel to the combustion chamber.

In Fig. 3 is shown a nozzle holder 26, a fuel supply line 2i, pressure adjusting spring 22 and screw 23 for adjusting the spring 22. The nozzle holder 20 is provided with the usual leak-off connection 24.

The tubular support 25 has a threaded portion 2%; adjacent theend thereof and corresponding to the threaded portion l3-on the nozzle support [3 and is adapted to engage a correspondingly threaded portion 21'on the adjacent end of the nozzle holder 20.

The nozzle holder 20 is adapted for use with the nozzle construction shown in Figs. 1, 2 or 3 and in the case of Fig. 1 is secured to the nozzle I by the coupling l2 and in the case of Fig. 2 is secured to the nozzle support l3 by the threaded extension [8 and the seat 28 for the pressure adjusting spring 22 which is adapted to engage the member 6 in the form of the invention shown in Figs. 1 and 2 in a similar manner to that in which it engages the valve actuating member 29 in Fig. 3.

In the form of the invention shown in Fig. 3, the nozzle tip 39 has a peripheral flange 3! adapted to engage the peripheral flange 32 on the member 25 whereby the nozzle tip is positioned in operative position and adapted to discharge fuel into the combustion chamber through the openings 33.

The member 34 is provided with the central bore 35 adapted to receive the valve stem 29 which engages the cup-shaped portion 36 on the upper end of the valve tip 31. The nozzle tip 30 is provided with the seat 38 adapted to be enga d by the seat 39 on the valve tip 31 to control the flow of fuel through the openings 33 to the combustion chamber.

It will be seen that in each form of the invention shown the valve is provided with a separate detachable tip which is self-aligning in its seat in the nozzle tip and, therefore, it is not necessary that the seat for the nozzle tip be perfectly aligned or concentric with the valve bore.

Also, because of the leak-off duct 8, fuel pressure behind the tips 9 and 31 will be relieved thereby allowing the valve tip to remain in contact with the valve stem at all times as a definite force differential is created on the ends of the tip from hydraulic pressure of the fuel.

The valve actuating member or piston 6 is actuated by the force of spring 22 and engages the upper end of the nozzle tips and normally retains the valve tips 9 or 31, in the constructions of Figs. 1 and 2, and Fig. 3 respectively in closed position until said valve tips are raised off their seats by the fuel pressure in which event they remain off their seats until the fuel pressure drops below the force of the spring 22 and the tips are then again forced into closed position.

From the foregoing it will be seen that we have provided simple, efiicient and economical means for obtaining all of the objects and advantages of the invention.

Having described our invention, we claim:

1. In a device of the character described, a nozzle having a bore and an opening for permitting the passage of fuel therefrom, a valve actuating member insaid bore and a tip separate from said member and adapted to control the flow of fuel through said opening, said tip 'being retained in engagement with said valve actuating member by fluid pressure only, and a leak-01f duct in said member to relieve any fuel pressure between said member and said tip.

2. In a device of the character described, a nozzle having a bore and an opening for permitting the passage of fuel therefrom, a valve actuating member in said bore and a tip separate from said member and adapted to control the flow of fuel through said opening, and a co-mating connection between said member and tip whereby said member Will be retained in engagement with said tip but said tip will be allowed to center I the flow of fuel through said opening, said tip being retained in engagement with said valve actuating member by fluid pressure only, and a leak-off duct extending longitudinally through said member.

4. In a device of the character described, a nozzle including a bore and an opening for the passage of fuel therefrom, a seat adjacent said opening, a valve actuating member in said bore and a separate valve tip having a seat adapted to engage said seat adjacent said opening to control the flow of fuel through said opening, and a co-mating connection between said valve actuating member and tip whereby said member will be retained in engagement with said tip but said tip will be allowed to center itself to close said opening, said tip being retained in engagement with said valve actuating member by fluid pressure only, and a duct through said member to relieve any fuel pressure from said co-mating connection.

THEODORE S. CHMURA. GEORGE E. WOOD, JR.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,490,734 Day Apr. 15, 1924 1,638,032 Himmelsbach Aug. 9, 1927 1,901,723 Belyavin Mar. 14, 1933 2,380,148 Camner July 10, 1945 FOREIGN PATENTS Number Country Date 358,340 Great Britain Oct. 8, 1941 777,261 France Nov. 26, 1934 

